Controlling Bacterial Biofilms in Cystic Fibrosis Airways

在这项研究中，我们描述了一种新的通路，它可能作为慢性阻塞性肺疾病(COPD)的启动者或辅助因子发挥作用，信号转导PMN的流入和对呼吸道的损害。具体地说，化学或酶解胶原蛋白释放三肽、Pgp和/或相关的Pgp序列，该序列在体外对PMN具有趋化作用。我们证明，将PGP引入呼吸道会引起PMN的强劲流入，但不会导致单核细胞的流入。值得注意的是，PGP的PMN趋化活性可能是由于与CXC趋化因子的受体结合域(如IL-8)具有明显的结构相关性，这些CXC趋化因子含有这个胶原蛋白序列或类似物。长时间的呼吸道暴露会导致肺泡扩大和右室肥厚，从而重述COPD的某些方面。此外，利用电喷雾电离-液-质联用(ESI-LC-MS/MS)技术，在雾化染毒动物的呼吸道中发现了Pgp，并对PMN的内流有显著贡献。我们通过系统地将L与P在N和/或C端的D异构体交换，将PGP从CXC受体(R)激动剂转化为部分激动剂，最后成为拮抗剂。(D-P)G(D-P)体外拮抗Pgp和IL-8趋化活性。我们发现Pgp存在于几乎所有COPD患者的支气管肺泡灌洗液(BALF)和/或痰中，但不存在于对照组或哮喘患者。此外，来自COPD患者而不是对照组的痰中含有从纯化的胶原蛋白体外产生PGP所需的所有酶机制。总而言之，这些发现使我们假设PGP是COPD的一个新的生物标记物，可能与疾病有关。作为推论，我们推测PGP是COPD的一个有吸引力的治疗靶点。这些假说将通过多学科、多方面的方法进行验证，以开发(D-P)G(D-P)作为一种新的治疗方法，它将同时抑制中性粒细胞炎症的IL-8和PGP途径，因此，可能对COPD的治疗有用。此外，我们将评估Pgp作为COPD的新生物标志物以及(D-P)G(D-P)作为治疗药物的潜在用途的预测指标。

In this proposal, we describe a new pathway signaling PMN influx and damage to the airways that may play a role as an initiator or cofactor for chronic obstructive pulmonary disease (COPD). Specifically, chemical or enzymatic breakdown of collagen releases a tripeptide, PGP, and/or a related PGP-containing sequence that is chemotactic for PMN in vitro. We demonstrate that introduction of PGP into the airways causes a robust influx of PMN, but not monocytes. Remarkably, the PMN chemotactic activity of PGP may be due to a marked structural relatedness to a receptor binding domain of CXC chemokines such as IL-8 which contain this collagen sequence or a close analog. Prolonged airway exposure to this peptide causes alveolar enlargement and right ventricular hypertrophy and thus recapitulates aspects of COPD. Furthermore, using electrospray ionization-liquid chromatography-mass spectrometry (ESI-LC-MS/MS), PGP is found in the airways of animals exposed to aerosolized LPS and markedly contributes to PMN influx. We have converted PGP from a CXC receptor (R) agonist to a partial agonist and finally an antagonist by systematically exchanging L with D isomers of P on the N and/or C termini. (D-P)G(D-P) antagonizes PGP as well as IL-8 chemotactic activity in vitro. We have found that PGP is present in bronchoalveolar lavage fluids (BALF) and/or sputum from virtually all COPD patients but not controls or asthmatics. Furthermore, sputum from COPD patients but not control individuals contains all the enzymatic machinery necessary for the ex vivo generation of PGP from purified collagen. Collectively, these findings lead us to hypothesize that PGP represents a novel biomarker for COPD that may contribute to disease. As a corollary, we theorize that PGP represents an attractive therapeutic target in COPD. These hypotheses will be tested via a multidisciplinary, multifaceted approach to develop (D-P)G(D-P) as a new therapeutic that will simultaneously inhibit both the IL- 8 and PGP pathways of neutrophilic inflammation and, consequently, may be useful in the management of COPD. In addition, we will evaluate PGP as a novel biomarker for COPD as well as a prognosticator of potential utility of (D-P)G(D-P) as a therapeutic agent.